DC Gay Marriage Catholic?

The Washington, D.C. Council voted 11-2 to legalize gay marriage prompting the Catholic Church to warn it will stop social services to the city if the measure is approved.
Why can't this people let other citizens be?

The Catholic Church is threatening to withhold its social services from the District because they're a bunch of lunatics.
The no votes came from Former Washington mayor Marion Barry and councilwoman Yvette Alexander.

The Catholic Church, through the Archdiocese of Washington, has threatened to end a longstanding network of social services if the city council passes the bill many times. Aren't they supposed to be good people?
The church says morally, it has no other choice.

Roman Catholics are quickly catching up to other denominations that have traditionally opposed gay rights, most notably Evangelical Christians and the Mormon Church. Catholic groups poured millions of dollars to anti-gay marriage referendum campaigns in California and Maine. Pope Benedict frequently speaks out against giving gay men and women the right to marry; often in Spain, where marriages of this type are legal.

There's nothing we can do about it, Catholic are not easy to convince.